461] COLORS OF TIGER BEETLES— SHELF ORD 67 



COLOR 



1. The brilliant colors of the group are due to thin surface films 

 of material having properties of metals. 



2. Changes in color during ontogeny are from green and blue toward 

 red or brown, except in C. lepida in which it is from yellow (gold) 

 to green; purples appear to stand apart from greenish blues and do 

 not change during ontogeny or if so only slightly. 



3. During ontogeny some species pass through stages correspond- 

 ing to geographic races, but the biogentic law is of doubtful applica- 

 tion, though green stages in ontogeny possess the same amount of pig- 

 ment as green races and the reds and brown which come later are as- 

 sociated with more pigment but not causally. 



GEOGRAPHY 



1. The center of distribution of the group is about the Indian 

 Ocean. 



2. Geographic races and geographic distribution is not correlated 

 with any observed climatic or meteorological conditions unless it be 

 rainfall and in this case the correlation is not complete. This lack of 

 correlation is believed to be due to a lack of records of soil conditions. 



3. Experimental modifications nearly duplicate certain geographic 

 races of the species concerned; these races occur in localities where 

 conditions are probably similar to the experimental condition. 



4. In the species studied in detail the more brilliant colors are 

 in warm arid localities, reduced marking in warm localities, and ex- 

 tended marking in cooler localities. 



